Am 01.06.2012 18:01, schrieb Chris Adams:
Once upon a time, Reindl Harald h.reindl@thelounge.net said:
DO NOT SPIT USELESS DATA IN MY RAM PER DEFAULT BECAUSE RAM IS EXPENSIVE STORAGE AND USED FOR BETTER THINGS
Actually, the data written to /tmp _always_ goes through the page cache and is held in RAM (at least for a bit). Since many things in /tmp are short-lived, they'll stay in the page cache for "life". The difference between /tmp-on-storage and /tmp-on-tmpfs is that tmpfs has no overhead for reading metadata from storage, allocating space, flushing updated metadata, etc.; the files just only exist in the same page cache they would have been in all along
but the data in /tmp are not forever in the cache
if it is tmpf and app dies after creating a 2 GB file in /tmp RAM will be filled until next reboot and leads sooner or later in swap-usage or OOM-killer
no, you do NOT want swap-usage in most workloads at all